To ensure database durability, RAID 1 (mirror disks)
was used for the database maintained on the
Sun StorEdge 3320 Arrays.
The application server has a pair of mirrored disks
(using Solaris Volume Manager) to provide
durability for the message queues.

Storage Requirement Info:

A 75 minute run at an injection rate of 531 increased storage by 451 MB
This extrapolates to 10.5 GB of storage for a 24 hour run.
The database is configured with 1752 GB of mirrored data storage.

The only errors in the driver log files were those that are normally generated by this benchmark.
Recoverable 2-phase transactions were used to coordinate the
the database server and JMS server using Sun's Last Agent
Optimization; the 1PC database transactions and transaction
written to the database in a single transaction.
DB2 uses "soft" checkpoints to ensure that no updates remain unflushed for
longer than the allowed time.
When DB2 UDB server modifies a database table, the change is initially
made in memory, not on disk. When there is not enough space in the memory
buffer to read in or write additional data pages, DB2 UDB Server will make
space by flushing some modified pages to disk. Modified pages are also
written to disk as part of the "Soft" checkpoint to ensure that no updates
remain unflushed for longer than the allowed time. Before a change is made
to the database, it is first recorded in the transaction log. This ensures
that the database can be recovered completely in the event of a failure.
Using the transaction log, transactions that started but did not complete
prior to a failure can be undone, and transactions recorded as complete in
the transaction log but not yet written to disk can be redone.
DB2 UDB uses a write-ahead-logging protocol to guarantee recovery. This
protocol uses "Soft" checkpoints to write least-recently-used database
pages to disk independent of transaction commit. However, enough log
information to redo/udo the change to a database page is committed to disk
before the database page itself is written. This protocol therefore renders
checkpoints unnecessary for DB2 UDB.

For questions about this result, please contact the submitter: Sun Microsystems Inc.
For other inquiries, please contact
webmaster@spec.org